Draba stenoloba


Fl. Ross. 1: 154. 1841.

Synonyms: Draba acinacis H. St. John Draba hirta var. siliquosa Chamisso & Schlechtendal Draba macouniana Rydberg Draba nemorosa var. stenoloba (Ledebour) M. E. Jones Draba nitida var. praelonga O. E. Schulz Draba oligantha Greene Draba stenoloba var. oligantha (Greene) O. E. Schulz
Treatment appears in FNA Volume 7. Treatment on page 340. Mentioned on page 272, 273, 276, 278, 282, 287, 289, 341.

Biennials or perennials; (short-lived, not cespitose); caudex simple (not fleshy); scapose. Stems often unbranched, (0.2–)0.4–3(–3.4) dm, pubescent proximally, usually glabrous distally, rarely sparsely pubescent, trichomes short-stalked, 2–4-rayed, 0.1–0.4(–0.5) mm. Basal leaves rosulate; petiole (obscure), margin ciliate, (trichomes simple, 0.2–0.4 mm); blade oblanceolate to obovate, 0.4–2.6(–3.1) cm × 1.5–7(–10) mm, margins entire or denticulate, (ciliate as petiole), surfaces pubescent, abaxially with short-stalked, 3- or 4-rayed trichomes, 0.1–0.5 mm, adaxially with simple and stalked, 2–4-rayed trichomes, 0.1–0.5 mm. Cauline leaves (0 or) 1 or 2 (3 or 4); sessile; blade elliptic to lanceolate or ovate, margins toothed, surfaces pubescent, abaxially with short-stalked 3- or 4-rayed trichomes, adaxially with simple and short-stalked, 2–4-rayed trichomes. Racemes (2–)4–10(–15)-flowered, ebracteate, elongated in fruit; rachis not flexuous, usually glabrous, rarely sparsely pubescent. Fruiting pedicels horizontal to divaricate-ascending, straight, 3–14(–19) mm (subequaling or shorter than fruit), usually glabrous, rarely pubescent, trichomes 2–4-rayed. Flowers (chasmogamous, petaliferous); sepals (green or purplish), oblong, 1.5–2.5 mm, glabrous or pubescent, (trichomes simple); petals yellow, oblanceolate, 2.5–3.5 × 0.6–1 mm; anthers ovate, 0.25–0.4 mm. Fruits linear or, rarely, linear-elliptic, plane, flattened, (8–)10–17(–20) × 1.5–2 mm; valves usually glabrous, rarely sparsely puberulent, trichomes simple; ovules 24–36 per ovary; style 0.01–0.15 mm. Seeds ovoid, 0.9–1 × 0.5–0.6 mm. 2n = 40.

Phenology: Flowering Jun–Jul.
Habitat: Grassy knolls, glacial moraines and creek banks, mesic meadows, alpine thickets
Elevation: 600-2300 m


V7 474-distribution-map.gif

Alta., B.C., Yukon, Alaska, Oreg., Wash.


Draba stenoloba is occasionally confused with D. albertina, but is easily recognized by having exclusively 2–4-rayed (versus mostly simple) trichomes on stems proximally. It is rarely encountered and apparently confined to the Pacific Northwest. In contrast, D. albertina is common and widespread in the mountains of western North America.

Selected References


Lower Taxa

... more about "Draba stenoloba"
Ihsan A. Al-Shehbaz +, Michael D. Windham +  and Reidar Elven +
Ledebour +
Alta. +, B.C. +, Yukon +, Alaska +, Oreg. +  and Wash. +
600-2300 m +
Grassy knolls, glacial moraines and creek banks, mesic meadows, alpine thickets +
Flowering Jun–Jul. +
Draba acinacis +, Draba hirta var. siliquosa +, Draba macouniana +, Draba nemorosa var. stenoloba +, Draba nitida var. praelonga +, Draba oligantha +  and Draba stenoloba var. oligantha +
Draba stenoloba +
species +